The long term objective of this study is to improve our understanding of how the spermatozoon interacts with its environment. This informaion should provide insights for new approaches to human contraception and for correcting problems of infertility. The post-testicular development of sperm in the male and female reproductive tracts is known to involve surface and membrane alterations as well as metabolic changes. The hypothesis we propose to test is that metabolic changes which occur in sperm in response to changes in the fluid environment are mediated via alterations in the plasms membrane. These membrane modifications would result in "communication" to the mitochondrion. Our first objective will be to establish that specific modifications of the cell membrane result in specific alterations of cell metabolism. This will be accomplished by reacting sperm with monoclonal and monospecific polyclonal antibodies to membrane proteins and determining how these treatments affect oxygen uptake and mitochondrial reduction of the spin label TEMPONE using electron spin resonance (ESR) techniques. For those treatments which result in altered metabolism our second objective will be to characterize in detail the nature of the membrane alteration by analysis of lipids using HPLC, proteins using 2-dimensional gel electrophoresis, and biophysical characteristics using ESR and spin label techniques for proteins, lipids and sialic acid. We also will localize the reacting antigen-antibody domains on the sperm surface using fluorescently tagged anti-IgG and the indirect method. The final objective of these studies will be to explore how singals from the plasma membrane are transferred to the mitochondrion. We will test whether the process is dependent on a "second messenger" such as adenylate cyclase by determining cAMP levels and using adenylate cyclase inhibitors. We will test the role of the cytoskeleton in transmitting information by using cytoskeleton inhibitors. We will determine whether sugar transport is altered by the treatment and whether receptor "clustering" at the cell surface is involved in the response. The results of these studies should be useful for understanding how components of fluids in the male and female reproductive tracts orchestrate events during the maturation and capacitation of spermatozoa.